There’s something about Audi’s flagship four-door that brings out the inner bad boy.

It doesn’t help that the S8 is packing a decidedly potent 520-horsepower, twin-turbo 4.0-litre V8. Still, it’s not as much the muscle under the hood as what can be done with it. I’m talking mayhem and carnage, which is what Hollywood has a propensity to do with large German sedans. Think Jason Statham in The Transporter flicks or Skipp Sudduth as Larry the wheelman in Ronin. Or, going back a bit, Clive Owen as “Driver” in BMW’s wonderful The Hire series of arty short films.

There’s a fair number of full-sized Eurosedans that also happen to go like stink when avoiding imminent peril. Along with the S8, you could choose any number of its competition — Jaguar XJR, Mercedes S63, BMW 760Li and, maybe, the Porsche Panamera Turbo S — as long as it’s subdued. No flashy colours, please; too conspicuous. In this regard, the big Audi wears an extra cloak of stealth, courtesy of the handsome and very muscular yet conservatively cut shape of its sheet metal. It also has a very high intimidation factor. Forget celluloid chase scenes, I’m talking the real world now. I haven’t seen as many slower-moving cars change lanes as I snuck up in their rear-view mirrors since I tested the formerly ubiquitous cop car Chevy Impala. Maybe it’s the bold shield-sized grille and the four rings that proclaim a freight train of a car is about to take a bite out of your bumper.

2015 Audi S8

Although the S8 is bred for the Autobahn, it doesn’t always need to be driven like it was stolen. Still, there is temptation; there’s a lovely burble coming from the exhaust even just puttering around town. And that sound turns ferocious when the gas pedal is pushed harder and the eight-speed’s shifter is slapped into Sport mode. With Quattro all-wheel-drive providing four-wheel traction — and 481 pound-feet of torque that comes on at a low 1,700 rpm and hangs on until 5,500 rpm — the 2,125-kilogram Audi launches itself like it was a Porsche 911. The company says 100 km/h takes but 4.1 seconds from a standing start.

Nobody considering a 500-plus-horsepower full-sized sedan as a daily driver is going to be overly concerned about fuel economy, but Audi at least makes an attempt through its cylinder on demand (COD) system, shutting down four of the eight cylinders when operating under part load. An Active Noise Cancellation system with active engine mounts suppress undesired noise and vibrations by producing precise anti-phase vibrations, so the big Audi doesn’t sound like an econobox when it’s trying to be frugal. Nor does it really succeed as one; I averaged 15.5 L/100 kilometres on 91 octane during my time with the car.

Any scofflaw activity, whether on screen or in actuality, is generally frowned on by polite society as well as the local constabulary. This means also looking at the S8 through a different set of eyes – one accustomed to the finer things in life rather than as an unrepentant Mario Andretti wannabe.

2015 Audi S8

The S8 may be aging — the A8 on which it is based has been around in its current form (albeit with periodic freshening) for six years — but it’s aging with grace. It moves and stops well for a big car, the air suspension has a solid, well-damped ride quality and there’s tenacious grip at normal speeds thanks to the Quattro all-wheel-drive system. I did find the steering just a little too light for my tastes, but it does make it easier to park the car. Speaking of which, the backup cameras – especially the “top-view” one – are excellent.

Inside is more of the same. Audi didn’t skimp on the luxury touches, nor should it considering the eye-watering $140,000 as-tested price tag. The grey dials and white needles of the analogue clock and the dial instruments characterize S-model interiors. The inlays are brushed aluminum and something resembling carbon-fibre, the door trim panels and the headrest are trimmed in Alcantara and the shift knob is carbon. The pedals and footrest have an aluminum-look finish and a red ring adorning the start-stop button accents the red S8 badge on the steering wheel. The sport seats are covered in perforated Valcona leather and feature diamond-quilted centre sections.

2015 Audi S8

All the modern conveniences are there — four-zone automatic air conditioning, a killer $7,000 Bang & Olufsen surround-sound system, navigation touchscreen, head-up display and much more. Is it as up-to-date technology-wise as some of the newer competition out there? Unlikely, but all the buttons are large, well-marked and the major controls fall easily to hand. In short, the car is as sophisticated as it needs to be.

The S8 is a rare beast; Audi sells less than 300 A8s a year in Canada, of which the S version is but a subset. Still, as with the aforementioned competition, the S8 projects the requisite blend of power, exclusivity and extravagance that something in its price range should. Its biggest detriment, at least for those with large egos, is its subtlety. On the other hand, if you’re hiring yourself out as someone who moves goods — human or otherwise — from one place to another with no questions asked, it’s the perfect stealth machine.